fMRI neural activation patterns induced by professional military training

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Krešimir Ćosić ◽  
Siniša Popović ◽  
Ivan Fabek ◽  
Bernard Kovač ◽  
Milan Radoš ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Military Training ◽  
Temporal Cortex ◽  
Well Being ◽  
Neural Activation ◽  
Neural Responses ◽  
Activation Patterns ◽  
Operational Capabilities ◽  
Posterior Parietal ◽  
Potential Failure

AbstractProfessional military training makes tough demands on soldiers’ perceptual and motor skills, as well as on their physical fitness and cognitive capabilities in the course of preparation for stressful operational environments. In this pilot study we attempted to identify difference in pattern of neural responses between extensively trained, professional mission-ready soldiers and novice soldiers during audiovisual simulation of mission conditions. We performed fMRI scanning on a few volunteers during presentation of semantically relevant video-clips of real combat from Afghanistan to evaluate influence of military training on mental responses of soldiers. We showed that for professional mission-ready soldiers a week before their deployment to Afghanistan, videoclips with deadly ambush combat induce greater overall brain activation compared to novice soldiers. Missionready soldiers showed greater activation in premotor/prefrontal cortex, posterior parietal cortex, and posterior temporal cortex. These results imply that fMRI technique could be used as challenging step forward in the multidimensional evaluation of military training influence on neural responses and operational capabilities of professional soldiers. This is extremely important not only for potential failure prevention and mere success of the mission, but even more for the survival and the well-being of the servicemen and servicewomen.

scholarly journals Evidence accumulation relates to perceptual consciousness and monitoring

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Pereira ◽  
Pierre Megevand ◽  
Mi Xue Tan ◽  
Wenwen Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Detection Threshold ◽  
Task Demands ◽  
Neuron Activity ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Neural Basis ◽  
Perceptual Consciousness ◽  
Evidence Accumulation ◽  
Posterior Parietal

AbstractA fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.

Comparison of subcortical connections of inferior temporal and posterior parietal cortex in monkeys

1993 ◽  
Vol 10 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Joan S. Baizer ◽  
Robert Desimone ◽  
Leslie G. Ungerleider
Keyword(s):  
Parietal Cortex ◽  
Visual Processing ◽  
Posterior Parietal Cortex ◽  
Temporal Cortex ◽  
Spatial Vision ◽  
Nucleus Basalis ◽  
Basal Nuclei ◽  
Processing Pathways ◽  
Posterior Parietal ◽  
Area Te

AbstractTo investigate the subcortical connections of the object vision and spatial vision cortical processing pathways, we injected the inferior temporal and posterior parietal cortex of six Rhesus monkeys with retrograde or anterograde tracers. The temporal injections included area TE on the lateral surface of the hemisphere and adjacent portions of area TEO. The parietal injections covered the posterior bank of the intraparietal sulcus, including areas VIP and LIP. Our results indicate that several structures project to both the temporal and parietal cortex, including the medial and lateral pulvinar, claustrum, and nucleus basalis. However, the cells in both the pulvinar and claustrum that project to the two systems are mainly located in different parts of those structures, as are the terminals which arise from the temporal and parietal cortex. Likewise, the projections from the temporal and parietal cortex to the caudate nucleus and putamen are largely segregated. Finally, we found projections to the pons and superior colliculus from parietal but not temporal cortex, whereas we found the lateral basal and medial basal nuclei of the amygdala to be reciprocally connected with temporal but not parietal cortex. Thus, the results show that, like the cortical connections of the two visual processing systems, the subcortical connections are remarkably segregated.

Decoding Episodic Retrieval Processes: Frontoparietal and Medial Temporal Lobe Contributions to Free Recall

2016 ◽  
Vol 28 (1) ◽  
pp. 125-139 ◽  
Author(s):  
James E. Kragel ◽  
Sean M. Polyn
Keyword(s):  
Free Recall ◽  
Temporal Lobe ◽  
Parietal Cortex ◽  
Medial Temporal Lobe ◽  
Posterior Parietal Cortex ◽  
Activity Patterns ◽  
Memory Search ◽  
Correct Identification ◽  
Neural Activation ◽  
Posterior Parietal

Neuroimaging studies of recognition memory have identified distinct patterns of cortical activity associated with two sets of cognitive processes: Recollective processes supporting retrieval of information specifying a probe item's original source are associated with the posterior hippocampus, ventral posterior parietal cortex, and medial pFC. Familiarity processes supporting the correct identification of previously studied probes (in the absence of a recollective response) are associated with activity in anterior medial temporal lobe (MTL) structures including the perirhinal cortex and anterior hippocampus, in addition to lateral prefrontal and dorsal posterior parietal cortex. Here, we address an open question in the cognitive neuroscientific literature: To what extent are these same neurocognitive processes engaged during an internally directed memory search task like free recall? We recorded fMRI activity while participants performed a series of free recall and source recognition trials, and we used a combination of univariate and multivariate analysis techniques to compare neural activation profiles across the two tasks. Univariate analyses showed that posterior MTL regions were commonly associated with recollective processes during source recognition and with free recall responses. Prefrontal and posterior parietal regions were commonly associated with familiarity processes and free recall responses, whereas anterior MTL regions were only associated with familiarity processes during recognition. In contrast with the univariate results, free recall activity patterns characterized using multivariate pattern analysis did not reliably match the neural patterns associated with recollective processes. However, these free recall patterns did reliably match patterns associated with familiarity processes, supporting theories of memory in which common cognitive mechanisms support both item recognition and free recall.

scholarly journals Functional versus effector-specific organization of the human posterior parietal cortex: revisited

2016 ◽  
Vol 116 (4) ◽  
pp. 1885-1899 ◽  
Author(s):  
Tobias Heed ◽  
Frank T. M. Leone ◽  
Ivan Toni ◽  
W. Pieter Medendorp
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Premotor Cortex ◽  
Action Representation ◽  
Functional Versus ◽  
Activation Patterns ◽  
Fine Grained ◽  
Fmri Signal ◽  
Repetition Suppression ◽  
Posterior Parietal

It has been proposed that the posterior parietal cortex (PPC) is characterized by an effector-specific organization. However, strikingly similar functional MRI (fMRI) activation patterns have been found in the PPC for hand and foot movements. Because the fMRI signal is related to average neuronal activity, similar activation levels may result either from effector-unspecific neurons or from intermingled subsets of effector-specific neurons within a voxel. We distinguished between these possibilities using fMRI repetition suppression (RS). Participants made delayed, goal-directed eye, hand, and foot movements to visual targets. In each trial, the instructed effector was identical or different to that of the previous trial. RS effects indicated an attenuation of the fMRI signal in repeat trials. The caudal PPC was active during the delay but did not show RS, suggesting that its planning activity was effector independent. Hand and foot-specific RS effects were evident in the anterior superior parietal lobule (SPL), extending to the premotor cortex, with limb overlap in the anterior SPL. Connectivity analysis suggested information flow between the caudal PPC to limb-specific anterior SPL regions and between the limb-unspecific anterior SPL toward limb-specific motor regions. These results underline that both function and effector specificity should be integrated into a concept of PPC action representation not only on a regional but also on a fine-grained, subvoxel level.

scholarly journals Action representation in the mouse parieto-frontal network

2019 ◽  
Author(s):  
Tuce Tombaz ◽  
Benjamin A. Dunn ◽  
Karoline Hovde ◽  
Ryan J. Cubero ◽  
Bartul Mimica ◽  
...  
Keyword(s):  
Mirror Neurons ◽  
Posterior Parietal Cortex ◽  
Wheel Running ◽  
Action Representation ◽  
Neural Responses ◽  
Brain Areas ◽  
Neural Ensembles ◽  
Sensorimotor Transformations ◽  
Posterior Parietal ◽  
Goal Directed Behavior

AbstractThe posterior parietal cortex (PPC), along with anatomically linked frontal areas, form a cortical network which mediates several functions that support goal-directed behavior, including sensorimotor transformations and decision making. In primates, this network also links performed and observed actions via mirror neurons, which fire both when an individual performs an action and when they observe the same action performed by a conspecific. Mirror neurons are thought to be important for social learning and imitation, but it is not known whether mirror-like neurons occur in similar networks in other species that can learn socially, such as rodents. We therefore imaged Ca2+ responses in large neural ensembles in PPC and secondary motor cortex (M2) while mice performed and observed several actions in pellet reaching and wheel running tasks. In all animals, we found spatially overlapping neural ensembles in PPC and M2 that robustly encoded a variety of naturalistic behaviors, and that subsets of cells could stably encode multiple actions. However, neural responses to the same set of observed actions were absent in both brain areas, and across animals. Statistical modeling analyses also showed that performed actions, especially those that were task-specific, outperformed observed actions in predicting neural responses. Overall, these findings show that performed and observed actions do not drive the same cells in the parieto-frontal network in mice, and suggest that sensorimotor mirroring in the mammalian cortex may have evolved more recently, and only in certain species.

scholarly journals Temporal Cortex Reflects Effects of Sentence Context on Phonetic Processing

2013 ◽  
Vol 25 (5) ◽  
pp. 706-718 ◽  
Author(s):  
Sara Guediche ◽  
Caden Salvata ◽  
Sheila E. Blumstein
Keyword(s):  
Speech Processing ◽  
Temporal Cortex ◽  
Superior Temporal Gyrus ◽  
Sentence Context ◽  
Middle Temporal Gyrus ◽  
Neural Activation ◽  
Sources Of Information ◽  
Activation Patterns ◽  
Two Factors ◽  
Language Context

Listeners' perception of acoustically presented speech is constrained by many different sources of information that arise from other sensory modalities and from more abstract higher-level language context. An open question is how perceptual processes are influenced by and interact with these other sources of information. In this study, we use fMRI to examine the effect of a prior sentence fragment meaning on the categorization of two possible target words that differ in an acoustic phonetic feature of the initial consonant, VOT. Specifically, we manipulate the bias of the sentence context (biased, neutral) and the target type (ambiguous, unambiguous). Our results show that an interaction between these two factors emerged in a cluster in temporal cortex encompassing the left middle temporal gyrus and the superior temporal gyrus. The locus and pattern of these interactions support an interactive view of speech processing and suggest that both the quality of the input and the potential bias of the context together interact and modulate neural activation patterns.

scholarly journals Separate Memory-Enhancing Effects of Reward and Strategic Encoding

2019 ◽  
Vol 31 (11) ◽  
pp. 1658-1673 ◽  
Author(s):  
Michael S. Cohen ◽  
Larry Y. Cheng ◽  
Ken A. Paller ◽  
Paul J. Reber
Keyword(s):  
Medial Temporal Lobe ◽  
Posterior Parietal Cortex ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Spatial Location ◽  
Strategic Control ◽  
A Value ◽  
Psychophysiological Interaction ◽  
Control Versus ◽  
Posterior Parietal

Memory encoding for important information can be enhanced both by reward anticipation and by intentional strategies. These effects are hypothesized to depend on distinct neural mechanisms, yet prior work has provided only limited evidence for their separability. We aimed to determine whether reward-driven and strategic mechanisms for prioritizing important information are separable, even if they may also interact. We examined the joint operation of both mechanisms using fMRI measures of brain activity. Participants learned abstract visual images in a value-directed recognition paradigm. On each trial, two novel images were presented simultaneously in different screen quadrants, one arbitrarily designated as high point value and one as low value. Immediately after each block of 16 study trials, the corresponding point rewards could be obtained in a test of item recognition and spatial location memory. During encoding trials leading to successful subsequent memory, especially of high-value images, increased activity was observed in dorsal frontoparietal and lateral occipitotemporal cortex. Furthermore, activity in a network associated with reward was higher during encoding when any image, of high or low value, was subsequently remembered. Functional connectivity between right medial temporal lobe and right ventral tegmental area, measured via psychophysiological interaction, was also greater during successful encoding regardless of value. Strategic control of memory, as indexed by successful prioritization of the high-value image, affected activity in dorsal posterior parietal cortex as well as connectivity between this area and right lateral temporal cortex. These results demonstrate that memory can be strengthened by separate neurocognitive mechanisms for strategic control versus reward-based enhancement of processing.

Sensorimotor cerebral activation during optokinetic nystagmus

Neurology ◽  
1997 ◽  
Vol 49 (5) ◽  
pp. 1370-1377 ◽  
Author(s):  
Stefan F. Bucher ◽  
Marianne Dieterich ◽  
Klaus C. Seelos ◽  
Thomas Brandt
Keyword(s):  
Posterior Parietal Cortex ◽  
Optokinetic Nystagmus ◽  
Object Motion ◽  
Cortical Activation ◽  
Subcortical Structures ◽  
Cerebral Activation ◽  
Activation Patterns ◽  
Medial Superior Temporal ◽  
Posterior Parietal ◽  
Self Motion

Self-motion or object motion can elicit optokinetic nystagmus (OKN), which is an integral part of dynamic spatial orientation. We used functional MR imaging during horizontal OKN to study cerebral activation patterns in sensory and ocular motor areas in 10 subjects. We found activation bilaterally in the primary visual cortex, the motion-sensitive areas in the occipitotemporal cortex (the middle temporal and medial superior temporal areas), and in areas known to control several types of saccades such as the precentral and posterior median frontal gyrus, the posterior parietal cortex, and the medial part of the superior frontal gyrus (frontal, parietal, and supplementary eye fields). Additionally, we observed cortical activation in the anterior and posterior parts of the insula and in the prefrontal cortex. Bilateral activation of subcortical structures such as the putamen, globus pallidus, caudate nucleus, and the thalamus traced the efferent pathways of OKN down to the brainstem. Functional MRI during OKN revealed a complex cerebral network of sensorimotor cortical and subcortical activation.

scholarly journals Task-Related c-Fos Expression in the Posterior Parietal Cortex During the “Rubber Tail Task” Is Diminished in Ca2+-Dependent Activator Protein for Secretion 2 (Caps2)-Knockout Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Makoto Wada ◽  
Kouji Takano ◽  
Masakazu Ide ◽  
Yoshitake Sano ◽  
Yo Shinoda ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Autism Spectrum ◽  
Neural Activation ◽  
Body Ownership ◽  
Neural Basis ◽  
Activator Protein ◽  
Posterior Parietal ◽  
Fos Expression ◽  
Cell Densities

Rubber hand illusion (RHI), a kind of body ownership illusion, is sometimes atypical in individuals with autism spectrum disorder; however, the brain regions associated with the illusion are still unclear. We previously reported that mice responded as if their own tails were being touched when rubber tails were grasped following synchronous stroking to rubber tails and their tails (a “rubber tail illusion”, RTI), which is a task based on the human RHI; furthermore, we reported that the RTI response was diminished in Ca2+-dependent activator protein for secretion 2-knockout (Caps2-KO) mice that exhibit autistic-like phenotypes. Importance of the posterior parietal cortex in the formation of illusory perception has previously been reported in human imaging studies. However, the local neural circuits and cell properties associated with this process are not clear. Therefore, we aimed to elucidate the neural basis of the RTI response and its impairment by investigating the c-Fos expression in both wild-type (WT) and Caps2-KO mice during the task since the c-Fos expression occurred soon after the neural activation. Immediately following the delivery of the synchronous stroking to both rubber tails and actual tails, the mice were perfused. Subsequently, whole brains were cryo-sectioned, and each section was immunostained with anti-c-Fos antibody; finally, c-Fos positive cell densities among the groups were compared. The c-Fos expression in the posterior parietal cortex was significantly lower in the Caps2-KO mice than in the WT mice. Additionally, we compared the c-Fos expression in the WT mice between synchronous and asynchronous conditions and found that the c-Fos-positive cell densities were significantly higher in the claustrum and primary somatosensory cortex of the WT mice exposed to the synchronous condition than those exposed to the asynchronous condition. Hence, the results suggest that decreased c-Fos expression in the posterior parietal cortex may be related to impaired multisensory integrations in Caps2-KO mice.

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